I've gotten some time to bang on Frictionless lately, and its going pretty well.
Things I've done:
ToolBar is an NSToolbar: The tools on top are now part of a tool bar. Which means you can show/hide them. So if you get the task list the way you want it, you can now hide all the panes but those, then hide even the toolbar.
Sync Services. Turns out with Leopard, its really easy to integrate with Sync Services if you're using CoreData. I'm not syncing with iCal, because I've come to believe that what I really need to do is coexist with iCal. That is, it would be better for me to come up with a "Today" view that showed you both your iCal items and your Frictionless items you've said you want to do today then it is for me to try to pull all your iCal items into Frictionless.
ToodleDo. So I've written code to export my Frictionless items into ToodleDo, whereupon I found that ToodleDo doesn't support fully hierarchical lists. Which is kind of a bummer. I couldn't find any other online to-do services that were fully hierarchical and had an API though. At this point the code is mostly one-way, I need to add syncing back down from ToodleDo for it to be fully functional.
Mail Sync. Leopard has the new scripting bridge code, so I was able to use that to move items in/out of designated folders in Mail. Coupled with Mail Act-On, that means that you can shove emails that need to become to-dos directly into the right folder with two keystrokes while you're reading mail. I already use Mail Act-On to do this now, so its no extra work for me.
That inspired me to build in a whole delegation mechanism, which is what I'm working on now. If you delegate a task, it bumps the start date (so you don't have to look at it), changes the task to "follow up w/ Foo Re: <previous title>", and optionally generates an email to that person. Once I have the import side of that finished, that means that if two people are both running frictionless they can exchange tasks pretty easily.
Templates. I fixed some bugs with Templates and made them work better. There's a new window that shows you all your top-level templates and presents a button that instantiates the template. This is great if you have something you have to do every so often that is a whole set of complex tasks.
Anyways, that's what's going on.